Waterways are often channelized or funneled into appropriate areas within a developed region. This procedure, either small or large scale, often includes construction of artificial water routes where storm water is collected or nearby streams or creeks are diverted and straightened. These concrete structures not only directly impact the surrounding habitat during construction, but also affect the nearby receiving water body by allowing increase flow to the system. Pollutant concentration is increased from urban runoff, and river or stream diversity is impacted due to increased water velocity, increased sediment load, and highly fluctuating water levels.
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Residential Channelization
Common to large scale channelization, residential methods also include straightening and diverting natural waterways away from specific areas. However, by creating a fenced bank lined in gravel, runoff water is able to penetrate the soil preventing higher velocities and increased sedimentation. Overall, however, this system is less functional than a good quality vegetative bank which offers shade and long-term adaptability to the stream/creek's demands.
Rivers and streams that run through urban or other predominantly developed areas are often poor quality systems that lack biodiversity in terms of both aquatic and vegetative organisms. These bodies of water are usually found along side of multiple lane roads and are frequently intersected by bridges. Significant stream banks, with adequate riparian cover are usually absent, thus resulting in higher flood levels with high rainfall and increased runoff and pollutant loading from nearby roads.
Areas under construction are devoid of any surface vegetation and topsoil and remain bare for extended periods of time. This process allows for extremely high quantities of subsoil to runoff into surrounding stormwater systems where receiving waters eventually accumulate large sediment loads. This increase in sediment decreases the amount of light penetrating through the water and thereby decreases the diversity and productivity of aquatic organisms.
Many urban areas and large developed regions have traditionally encroached on natural waterways. Originally for transportation and shipping purposes, towns were built up and around large rivers. While directly beneficial, such development takes it toll on the natural order of the water system. With the cumulative effects of impervious roadways, compacted nutrient poor soil, and lack of stabilizing vegetation buffers, nearby water sources are targets of various nonpoint pollutants and runoff from the surrounding area. Focus of future developments in such areas should be cautiously planned and should include watershed friendly areas such as wetlands, riparian, and biologically diverse areas.